JP6350346B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to an ink jet recording apparatus.

  2. Description of the Related Art Conventionally, in an ink jet recording apparatus that discharges ink onto a recording medium, a technique for removing paper dust is known in order to suppress the occurrence of nozzle clogging in a recording head.

  For example, an ink jet recording apparatus is disclosed in which a paper dust collecting member is disposed upstream of the recording head in the conveyance direction of the recording medium (see Patent Document 1). The paper dust collecting member includes a vertical wall and a downstream side wall. The vertical wall rises vertically upward. The downstream side wall extends from the upper end of the vertical wall toward the downstream side in the conveyance direction of the recording medium.

  In Patent Document 1, paper dust generated as the recording medium is conveyed is collected by the paper dust collecting member before reaching the recording head, so that the amount of paper dust adhering to the recording head is reduced. It is stated that you can.

JP 2008-213255 A

  However, in the ink jet recording apparatus described in Patent Document 1, paper dust is not effectively removed because paper dust is attached to the paper dust collecting member and removed. Further, even if paper dust adheres to the paper dust collecting member, the adhered paper dust falls from the paper dust collecting member and, for example, adheres to the recording paper and is transported to the recording head. There is a risk of adhesion.

  In the ink jet recording apparatus, fine ink droplets (hereinafter referred to as “mist”) are ejected from the recording head together with ink droplets for forming an image. Further, when the ink droplets land on the recording medium, a bounce mist that bounces off the recording medium is generated. These mists may adhere to the recording head.

  The present invention has been made in view of the above problems, and an object thereof is to provide an ink jet recording apparatus capable of effectively removing paper dust and mist.

  The ink jet recording apparatus of the present invention includes a recording head, a transport unit, and a first negative pressure applying unit. The recording head ejects ink onto a recording medium. The transport unit transports the recording medium to an image forming position by the recording head. The first negative pressure application unit applies a negative pressure to the recording medium at the image forming position. The first negative pressure applying unit includes a first negative pressure generating unit and a first negative pressure chamber. The first negative pressure generator generates a negative pressure. The first negative pressure chamber stores negative pressure air generated by the first negative pressure generator. In the first negative pressure chamber, a first filter is disposed substantially parallel to a plane perpendicular to the thickness direction of the recording medium conveyed to the image forming position. The first filter blocks the ink and allows air to pass through.

  According to the ink jet recording apparatus of the present invention, paper dust and mist can be effectively removed.

It is a figure which shows the structure of the inkjet recording device which concerns on this embodiment. FIG. 2 is a diagram illustrating a configuration of an image forming unit illustrated in FIG. 1. FIG. 3 is a cut perspective view illustrating configurations of a conveyance belt, a guide member, and a negative pressure application unit illustrated in FIG. 2. It is a top view which shows the structure of the guide member shown in FIG. It is the top view and sectional drawing which show the structure of the groove | channel and through-hole which were formed in the guide member shown in FIG. (A) is a top view which shows the structure of a groove | channel and a through-hole. (B) is AA sectional drawing of the groove | channel and through-hole which are shown to (a). It is a figure which shows the structure of the plate-shaped member vicinity shown in FIG. FIG. 3 is a diagram showing a configuration in the vicinity of a recording head shown in FIG. FIG. 8 is a diagram illustrating a comparative example of the configuration in the vicinity of the recording head illustrated in FIG. 7. It is a figure which shows the flow of the air at the time of reversely rotating the suction fan of the 2nd negative pressure generation part shown in FIG. It is side surface sectional drawing which shows the structure of the comparative example of the filter shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings (FIGS. 1 to 10). In the drawings, the same or corresponding parts are denoted by the same reference numerals and description thereof is not repeated.

  First, an ink jet recording apparatus 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a configuration of an inkjet recording apparatus 1 according to the present embodiment. The ink jet recording apparatus 1 includes an apparatus casing 100, a sheet feeding unit 2 disposed below the inside of the apparatus casing 100, an image forming unit 3 disposed above the sheet feeding unit 2, and one side of the image forming unit 3. A sheet transport unit 4 disposed on the right side in FIG. 1 and a sheet discharge unit 5 disposed on the other side (left side in FIG. 1) of the image forming unit 3 are provided.

  The paper feed unit 2 includes a paper feed cassette 21, a paper feed roller 22, and a guide plate 23. The paper feed cassette 21 stores recording paper P and is detachable from the apparatus housing 100. The paper feed roller 22 is disposed above one end (the right end in FIG. 1) of the paper feed cassette 21. The guide plate 23 is disposed between the paper feed roller 22 and the paper transport unit 4.

  A plurality of recording papers P are stored in the paper feed cassette 21. Hereinafter, “recording paper” is simply referred to as “paper” for convenience. The recording paper P corresponds to an example of “recording medium”. The paper feed roller (pickup roller) 22 is a roller that feeds the paper P along the transport direction D1 of the paper P, and takes out the paper P in the paper feed cassette 21 one by one from the top. The guide plate 23 guides the paper P taken out by the paper feed roller 22 to the paper transport unit 4.

  The paper transport unit 4 includes a substantially C-shaped paper transport path 41, a first transport roller pair 42 provided on the entrance side of the paper transport path 41, a second transport roller pair 43 provided in the middle of the paper transport path 41, In addition, a registration roller pair 44 provided on the exit side of the paper conveyance path 41 is provided.

  The first transport roller pair 42 is a roller pair (feed roller pair) that feeds the paper P along the transport direction of the paper P, and sends the paper P supplied from the paper feed unit 2 to the paper transport path 41. To do. The second transport roller pair 43 is also a feed roller pair. The second transport roller pair 43 feeds the paper P sent by the first transport roller pair 42 toward the registration roller pair 44 across the paper P.

  The registration roller pair 44 performs skew correction of the paper P that has been transported by the second transport roller pair 43. In addition, the registration roller pair 44 temporarily stops the paper P in order to synchronize the timing of image formation on the paper P and the conveyance timing of the paper P, and then sets the paper P to the image formation timing. Send to forming unit 3.

  The image forming unit 3 includes a transport belt 32 and a recording head 34, and transports the paper P supplied from the registration roller pair 44 in a predetermined direction (leftward in FIG. 1) by the transport belt 32 and transports by the transport belt 32. An image is formed by the recording head 34 on the paper P being printed. The detailed configuration of the image forming unit 3 will be described later with reference to FIG. Further, the image forming unit 3 includes a conveyance guide 36 on the downstream side (left side in FIG. 1) in the conveyance direction D1 of the paper P with respect to the recording head 34.

  The transport guide 36 guides the paper P discharged from the transport belt 32 to the paper discharge unit 5. The paper discharge unit 5 includes a discharge roller pair 51 and a discharge tray 52. The discharge tray 52 is fixed to the apparatus casing 100 so as to protrude outward from the discharge port 11 formed in the apparatus casing 100.

  The discharge roller pair 51 sends the paper P that has passed through the conveyance guide 36 toward the discharge port 11. The discharge tray 52 guides the paper P sent out by the discharge roller pair 51. The paper P sent out by the discharge roller pair 51 is discharged to the outside of the apparatus housing 100 through the discharge port 11 formed on one side surface (left side surface in FIG. 1) of the apparatus housing 100. The discharge tray 52 stacks and stores the paper P discharged from the discharge port 11.

  Next, the image forming unit 3 will be described with reference to FIG. FIG. 2 is a diagram showing the configuration of the image forming unit 3 shown in FIG.

  As shown in FIG. 2, the image forming unit 3 includes a transport unit 31, a negative pressure applying unit 33, four types of recording heads 34 (34 a, 34 b, 34 c, and 34 d), and a plate-like member 35. Each of the four types of recording heads 34a, 34b, 34c, and 34d is provided with a plurality of nozzles (not shown). Ink is ejected from the plurality of nozzles to form images such as characters and figures on the paper P. Since the recording heads 34a, 34b, 34c, and 34d have substantially the same configuration, they may be collectively referred to as the recording head 34.

  The transport unit 31 transports the paper P in a predetermined direction (leftward in FIG. 2), and includes a belt speed detection roller 311, a suction roller 312, a drive roller 313, a tension roller 314, a pair of guide rollers 315, and A transport belt 32 is provided.

  The transport unit 31 is disposed in the apparatus housing 100 so as to face the four types of recording heads 34 (34a, 34b, 34c, and 34d). The conveyance belt 32 is stretched around a belt speed detection roller 311, a driving roller 313, a tension roller 314, and a pair of guide rollers 315. The transport belt 32 is driven in the transport direction D1 (counterclockwise in FIG. 2) of the paper P to transport the paper P.

  The tension roller 314 applies tension to the conveyance belt 32 so that the conveyance belt 32 does not bend.

  The belt speed detection roller 311 is arranged on the upstream side (the right side in FIG. 2) in the transport direction D1 of the paper P with respect to the negative pressure application unit 33, and rotates due to the frictional force with the transport belt 32. The belt speed detection roller 311 includes a pulse plate (not shown), and the pulse plate rotates integrally with the belt speed detection roller 311. By measuring the rotational speed of the pulse plate, the rotational speed of the conveyor belt 32 is detected.

  The drive roller 313 is disposed on the downstream side (left side in FIG. 1) in the transport direction D1 of the paper P with respect to the negative pressure application unit 33.

  The driving roller 313 is rotationally driven by a motor (not shown), and rotates the conveying belt 32 in the counterclockwise direction of FIG.

  The pair of guide rollers 315 are disposed below the negative pressure application unit 33 and form a space below the negative pressure application unit 33. By arranging the pair of guide rollers 315 in this way, contact between the conveyance belt 32 and the negative pressure application unit 33 below the negative pressure application unit 33 can be prevented.

  The four types of recording heads 34 (34a, 34b, 34c, and 34d) are arranged in parallel from the upstream side to the downstream side in the transport direction D1 of the paper P. Each of the recording heads 34a, 34b, 34c, and 34d includes a plurality of nozzles (not shown) arranged in the width direction of the transport belt 32 (in FIG. 2, the direction orthogonal to the paper surface). The recording heads 34a, 34b, 34c, and 34d are called a line type. That is, the ink jet recording apparatus 1 is a line head type ink jet recording apparatus.

  The negative pressure application unit 33 includes a first negative pressure application unit 33 b, a second negative pressure application unit 33 a, and a guide member 332, and applies a negative pressure to the paper P via the conveyance belt 32, so that the paper P Is adsorbed to the conveyor belt 32. The first negative pressure application unit 33 b applies a negative pressure to the paper P at the image forming position below the recording head 34. The second negative pressure application unit 33 a applies a negative pressure to the paper P conveyed below the plate-like member 35. The first negative pressure application unit 33b is disposed on the back side (lower side in FIG. 2) of the conveyance belt 32 so as to face the four types of recording heads 34 with the conveyance belt 32 interposed therebetween. The second negative pressure application unit 33 a is disposed on the back side (lower side in FIG. 2) of the transport belt 32 so as to face the plate-like member 35 with the transport belt 32 interposed therebetween.

  The first negative pressure application unit 33b includes a first air circulation chamber 331b, a first negative pressure generation unit 336b, and a first exhaust port 337b. The second negative pressure application unit 33a includes a second air circulation chamber 331a, a second negative pressure generation unit 336a, and a second exhaust port 337a. The guide member 332 covers the upper surface opening of the first air circulation chamber 331b and the upper surface opening of the second air circulation chamber 331a.

  The suction roller 312 is a driven roller. The suction roller 312 is disposed to face the guide member 332 via the transport belt 32, guides the paper P sent from the registration roller pair 44 onto the transport belt 32, and causes the transport belt 32 to suck the paper P.

  The guide member 332 supports the paper P via the transport belt 32. Further, a through hole 335 is formed in the guide member 332.

  In the present embodiment, for the sake of convenience, the negative pressure application unit 33 is described as including the guide member 332. However, as described above, the guide member 332 supports the conveyance belt 32, so the conveyance unit 31 supports the guide member 332. It may be described as provided.

  The first air circulation chamber 331b and the second air circulation chamber 331a are formed by a bottomed cylindrical box-shaped member whose upper surface is open. The upper surfaces of the side walls constituting the first air circulation chamber 331b and the second air circulation chamber 331a are fixed to the guide member 332. The first negative pressure generation unit 336b and the second negative pressure generation unit 336a are disposed below the first air circulation chamber 331b and the second air circulation chamber 331a, respectively. The bottom wall of the box-shaped member constituting the first air circulation chamber 331b and the second air circulation chamber 331a has air at a position corresponding to the first negative pressure generation portion 336b and the second negative pressure generation portion 336a. An opening for distribution is provided. A first exhaust port 337b and a second exhaust port 337a are provided on the downstream side (lower side in FIG. 2) of the first negative pressure generating unit 336b and the second negative pressure generating unit 336a with respect to the air flow, respectively. Has been placed. When the first negative pressure generation unit 336b and the second negative pressure generation unit 336a are driven, negative pressure is generated in the first air circulation chamber 331b and the second air circulation chamber 331a, respectively. The negative pressure causes the paper P to be sucked toward the transport belt 32 through the guide member 332 and the transport belt 32.

  The first negative pressure generator 336b and the second negative pressure generator 336a generate negative pressure in the first air circulation chamber 331b and the second air circulation chamber 331a, respectively. It is a suction fan.

  Further, each of the first air circulation chamber 331b and the second air circulation chamber 331a is parallel to a plane perpendicular to the thickness direction of the paper P placed on the conveyor belt 32 (in FIG. 2, left and right). The first filter 339 and the second filter 338 are arranged in the direction). The 1st filter 339 and the 2nd filter 338 are comprised, for example from a nonwoven fabric, and remove paper dust and mist. The first filter 339 is disposed below the recording head 34 and mainly removes mist. The second filter 338 is disposed below the plate-like member 35 and mainly removes paper dust.

  The plate-like member 35 is arranged on the upstream side (the right side in FIG. 2) in the transport direction D1 of the paper P with respect to the recording head 34. In other words, the plate-like member 35 is disposed between the recording head 34 a and the suction roller 312. Further, the plate-like member 35 forms a narrow space 35 a between the upper surface of the transport belt 32. The plate member 35 corresponds to an example of a “space forming portion”.

  Next, the operation of the inkjet recording apparatus 1 will be described with reference to FIG. The paper feed roller 22 takes out the paper P from the paper feed cassette 21. The taken paper P is guided to the first transport roller pair 42 by the guide plate 23.

  The paper P is sent into the paper transport path 41 by the first transport roller pair 42 and is transported in the transport direction of the paper P by the second transport roller pair 43. Then, the sheet P comes into contact with the registration roller pair 44 and stops, and skew correction is performed. Then, the sheet P is sent to the image forming unit 3 by the registration roller pair 44 in accordance with the image forming timing.

  The paper P is guided onto the transport belt 32 by the suction roller 312 and is attracted to the transport belt 32. The paper P covers a part of a large number of suction holes 321 (see FIG. 3) formed in the transport belt 32. The first negative pressure application unit 33b and the second negative pressure application unit 33a suck air through the guide member 332 and the conveyor belt 32, and the first air circulation chamber 331b and the second air. A negative pressure is generated in the circulation chamber 331a. As a result, negative pressure acts on the paper P, and the paper P is attracted to the transport belt 32. The paper P is transported in the transport direction D1 of the paper P as the transport belt 32 moves.

  Each portion of the paper P is continuously conveyed by the conveyance belt 32 to positions facing the four types of recording heads 34a, 34b, 34c, and 34d. During this time, ink of each color is ejected from the four types of recording heads 34a, 34b, 34c, and 34d toward the paper P being transported by the transport belt 32. As a result, an image is formed on the paper P.

  The paper P is transported from the transport belt 32 to the transport guide 36. The sheet P that has passed through the conveyance guide 36 is sent in the direction of the discharge port 11 by the discharge roller pair 51, guided to the discharge tray 52, and discharged to the outside of the apparatus housing 100 through the discharge port 11.

  Next, with reference to FIG. 3, the structure of the conveyance belt 32, the guide member 332, and the negative pressure application part 33 is demonstrated. FIG. 3 is a cut perspective view illustrating the configuration of the conveyance belt 32, the guide member 332, and the negative pressure application unit 33 illustrated in FIG. The first negative pressure application unit 33b and the second negative pressure application unit 33a have substantially the same configuration, and may be collectively referred to as the negative pressure application unit 33. Similarly, the first air circulation chamber 331b and the second air circulation chamber 331a are collectively referred to as the air circulation chamber 331, and the first negative pressure generator 336b and the second negative pressure generator 336a are the negative pressure generator. 336 may be collectively referred to.

  As shown in FIG. 3, the conveyance belt 32, the guide member 332, the air circulation chamber 331, and the negative pressure generation unit 336 are arranged from the upper side to the lower side. A number of suction holes 321 are formed in the transport belt 32. A second filter 338 (or first filter 339) is disposed in the air circulation chamber 331.

  Here, the suction holes 321 formed in the transport belt 32 will be described. As shown in FIG. 3, a plurality of suction holes 321 are formed in the conveyor belt 32 at substantially equal intervals.

  In addition, a plurality of grooves 334 are formed on the upper surface of the guide member 332 (the surface on the conveying belt 32 side). The groove 334 is formed in an oval shape extending in the transport direction D1 of the paper P.

  Next, the groove 334 and the through hole 335 formed in the guide member 332 will be described with reference to FIG. 4 is a plan view showing the configuration of the guide member 332 shown in FIG. As shown in FIG. 4, the guide member 332 has a row of oval grooves 334 extending in the transport direction D1 (left and right direction in FIG. 4) of the paper P, in the width direction of the guide member 332 (in FIG. 4). A plurality of lines are formed in the vertical direction. In addition, a through hole 335 that penetrates the guide member 332 in the thickness direction is formed in the groove 334 at a substantially central position in the conveyance direction D1 (left and right direction in FIG. 4) of the paper P. The cross section of the through hole 335 is circular.

  The broken line shown in FIG. 4 indicates the position of the plate-like member 35 projected onto the guide member 332. With respect to the projection image of the plate-like member 35 on the guide member 332, the upstream side in the transport direction D1 of the paper P (left side in FIG. 4) and the downstream side in the transport direction D1 of the paper P (right side in FIG. 4). The through holes 335 are formed one by one. A groove 334 that communicates with a through hole 335 formed on the upstream side (left side in FIG. 4) in the transport direction D1 of the paper P is an upstream side in the transport direction D1 of the paper P in the projection image of the plate-like member 35 (see FIG. In FIG. 4, the sheet P extends further upstream in the transport direction D1 of the paper P than the position of the left edge. Similarly, the groove 334 communicating with the through hole 335 formed on the downstream side (right side in FIG. 4) in the transport direction D1 of the paper P is the downstream side in the transport direction D1 of the paper P in the projection image of the plate member 35 ( In FIG. 4, it extends further downstream in the transport direction D1 of the paper P than the position of the right edge.

  Next, the groove 334 and the through hole 335 formed in the guide member 332 will be described with reference to FIG. FIG. 5 is a plan view and a cross-sectional view showing the configuration of the groove 334 and the through hole 335 formed in the guide member 332 shown in FIG. 5A is a plan view showing the configuration of the groove 334 and the through hole 335, and FIG. 5B is a cross-sectional view taken along the line AA of the groove 334 and the through hole 335 shown in FIG. 5A. .

  As shown in FIG. 5A, the groove 334 penetrates the guide member 332 in the thickness direction at a substantially central position in the conveyance direction D1 of the paper P (left and right direction in FIG. 5A). A hole 335 is formed. As shown in FIG. 5B, since the groove 334 is formed so as to communicate with the through hole 335, the negative pressure applied from the air circulation chamber 331 via the through hole 335 forms the groove 334. It also affects the area where it is.

  Next, the configuration in the vicinity of the plate-like member 35 will be described with reference to FIG. FIG. 6 is a diagram showing a configuration in the vicinity of the plate-like member 35 shown in FIG.

  In the narrow space 35a, the velocity of the airflow flowing into the narrow space 35a from the space around the narrow space 35a is larger after flowing into the narrow space 35a than before flowing into the narrow space 35a. Thus, the distance HN in the direction orthogonal to the upper surface of the conveyor belt 32 is set. In other words, the distance HN is the length (distance) in the vertical direction of the narrow space 35a. In the following description, the distance HN in the direction perpendicular to the upper surface of the conveyance belt 32 in the narrow space 35a is referred to as the vertical length (distance) of the narrow space 35a for convenience.

  Specifically, the lower surface of the plate-like member 35 is between the upper surface of the transport belt 32 and the narrow space 35a in which the vertical distance HN is set to a predetermined threshold distance HS (for example, 3 mm) or less. Form. The plate-like member 35 is a conductor (for example, a metal such as stainless steel) having at least a lower surface thereof grounded. The upper surface of the conveyor belt 32 that is in contact with the guide member 332 corresponds to an example of a “recording medium placement surface”. In the present embodiment, the vertical distance HN of the narrow space 35a is, for example, 2 mm.

  The second filter 338 is parallel to the plane perpendicular to the thickness direction (vertical direction in FIG. 6) of the paper P placed on the transport belt 32 in the second air circulation chamber 331a (horizontal direction in FIG. 6). To). Specifically, the second filter 338 is disposed at a distance H1 from the upper surface of the second air circulation chamber 331a (the bottom surface of the guide member 332) and a distance H2 from the bottom surface of the second air circulation chamber 331a. However, the distance H2 is longer than the distance H1. In other words, the second filter 338 is disposed above the center position in the vertical direction in the second air circulation chamber 331a.

  The second filter 338 includes a filter main body 338a and a frame body 338b. The filter body 338a is composed of a nonwoven fabric. The frame body 338b is made of, for example, stainless steel or aluminum, and is disposed around the filter body 338a to support the filter body 338a.

  Guide grooves 331d and 331e are formed on the side surface of the second air circulation chamber 331a. By inserting the frame body 338b of the second filter 338 into the guide grooves 331d and 331e, the second filter 338 is mounted in the second air circulation chamber 331a. Further, the second filter 338 can be removed by pulling out the frame body 338b of the second filter 338 from the guide grooves 331d and 331e to the front side (or back side) in FIG.

  Next, the flow of air in the vicinity of the narrow space 35a will be described. Since the second air circulation chamber 331a is in a negative pressure state (for example, about 0.005 atm ≈ about 500 Pa) with respect to the atmospheric pressure by the second negative pressure generating unit 336a, the plurality of suction holes 321 and The air flows from the narrow space 35a into the second air circulation chamber 331a through the plurality of through holes 335. Further, since air flows into the second air circulation chamber 331a from the narrow gap space 35a, the upstream side (right side in FIG. 6) of the paper P in the transport direction D1 with respect to the plate member 35 and the transport direction of the paper P Air flows into the narrow space 35a from the downstream side of D1 (left side in FIG. 6).

  Therefore, air flows along arrows FD1 and FD2 shown in FIG. Since the vertical distance HN of the narrow space 35a is set to be equal to or smaller than a preset threshold distance HS, the air flow speed (wind speed) in the narrow space 35a increases. The wind speed in the narrow space 35a is preferably 6.0 m / second or more, for example.

  As described above, the wind indicated by the arrow FD1 blows from the upstream side to the downstream side in the conveyance direction D1 of the paper P in the narrow space 35a (to the left in FIG. 6). The paper dust PD adhering to the front end (left end in FIG. 6) of the paper P can be removed, and the removed paper dust PD can be collected on the second filter 338. Further, since the wind indicated by the arrow FD2 blows from the downstream side to the upstream side in the conveyance direction D1 of the paper P in the narrow space 35a (to the right in FIG. 6), as shown in FIG. The paper dust PD adhering to the rear end (right end in FIG. 6) can be removed, and the removed paper dust PD can be collected on the second filter 338. Therefore, the paper dust PD adhering to the paper P can be effectively removed.

  Further, as described above, since the plate member 35 is a grounded conductor, the plate member 35 is not charged. Therefore, even when the paper dust PD is charged, the adhesion of the paper dust PD to the plate-like member 35 can be suppressed.

  Furthermore, as described above with reference to FIG. 4, the groove 334 is formed at a position facing the plate-like member 35, so that the negative pressure applied from the second air circulation chamber 331 a through the through hole 335 is applied. This also acts on the region where the groove 334 is formed. Therefore, since air becomes easier to flow along the arrows FD1 and FD2 shown in FIG. 6, the paper dust PD can be more effectively removed.

  In addition, since the second filter 338 is configured to be detachable from the second air circulation chamber 331a, it can be easily replaced when the second filter 338 becomes dirty.

  Further, since the frame body 338b of the second filter 338 can be inserted or pulled out along the guide grooves 331d and 331e, the second filter 338 can be attached and detached more easily.

  The second filter 338 includes a frame body 338b that supports the filter main body 338a. Since the frame body 338b is made of stainless steel or aluminum, the second filter 338 is slid with the guide groove 331d and the guide groove 331e. Dynamic resistance can be reduced. Therefore, the second filter 338 can be replaced more easily.

  Next, the positional relationship between the suction hole 321 and the groove 334 will be described with reference to FIG. A plurality of rows of suction holes 321 arranged in the transport direction D1 of the paper P are formed in the width direction of the transport belt 32 (a direction perpendicular to the transport direction D1 of the paper P). The rows are arranged so that the suction holes 321 are arranged in a staggered manner. As shown in FIG. 3, the rows of the plurality of suction holes 321 of the conveyor belt 32 are respectively arranged corresponding to the rows of the plurality of grooves 334.

  The plurality of grooves 334 are formed so as to face at least two suction holes 321, respectively. As the transport belt 32 moves, the opposing suction holes 321 are replaced one by one in the plurality of grooves 334, respectively.

  The air circulation chamber 331 that is set to a negative pressure by the negative pressure generator 336 communicates with the suction hole 321 of the transport belt 32 through the through hole 335 and the groove 334 of the guide member 332.

  As described above, since the negative pressure is applied to the suction hole 321 of the transport belt 32, the transport belt 32 can suck and transport the paper P.

  Next, the configuration in the vicinity of the recording head 34 will be described with reference to FIG. FIG. 7 is a diagram showing a configuration in the vicinity of the recording head 34 shown in FIG.

  The first filter 339 is parallel to a plane perpendicular to the thickness direction (vertical direction in FIG. 7) of the paper P placed on the conveyor belt 32 in the first air circulation chamber 331b (horizontal direction in FIG. 7). To). Specifically, the first filter 339 is disposed at a distance H1 from the upper surface of the first air circulation chamber 331b (the bottom surface of the guide member 332) and a distance H2 from the bottom surface of the first air circulation chamber 331b. However, the distance H2 is longer than the distance H1. In other words, the first filter 339 is disposed above the center position in the vertical direction in the first air circulation chamber 331b.

  The first filter 339 includes a filter main body 339a and a frame body 339b. The filter body 339a is composed of a nonwoven fabric. The frame 339b is made of, for example, stainless steel or aluminum, and is disposed around the filter body 339a to support the filter body 339a.

  Guide grooves 331f and 331g are formed on the side surface of the first air circulation chamber 331b. The first filter 339 is attached to the first air circulation chamber 331b by inserting the frame body 339b of the first filter 339 into the guide grooves 331f and 331g.

  Next, the air flow in the vicinity of the recording head 34 will be described. The first air circulation chamber 331b is in a negative pressure state (for example, about 0.005 atm ≈ about 500 Pa) with respect to the atmospheric pressure by the first negative pressure generator 336b. The air flows from the space below the recording head 34 into the first air circulation chamber 331b through the plurality of through holes 335.

  Therefore, air flows along the arrows FC1 and FC2 shown in FIG. Since the wind indicated by the arrow FC1 blows downward in the vicinity of the recording head 34, the mist staying in the vicinity of the recording head 34 can be removed, and the removed mist can be collected on the first filter 339.

  In addition, the wind indicated by the arrow FC2 blows from the first filter 339 toward the first negative pressure generator 336b. As shown in FIG. 7, since the first filter 339 is disposed above the center position in the vertical direction in the first air circulation chamber 331b, the first filter 339 is connected to the first negative pressure generator 336b. The pressure loss due to the air flow can be reduced.

  Further, since the first filter 339 is configured to be detachable from the first air circulation chamber 331b, it can be easily replaced when the first filter 339 becomes dirty.

  Further, since the frame body 339b of the first filter 339 can be inserted or pulled out along the guide grooves 331f and 331g, the first filter 339 can be attached and detached more easily.

  The first filter 339 includes a frame body 339b that supports the filter main body 339a. Since the frame body 339b is made of stainless steel or aluminum, the first filter 339 slides with the guide groove 331f and the guide groove 331g. Dynamic resistance can be reduced. Therefore, the first filter 339 can be replaced more easily.

  Next, a comparative example of the configuration in the vicinity of the recording head 34 shown in FIG. 7 will be described with reference to FIG. FIG. 8 is a diagram showing a comparative example of the configuration in the vicinity of the recording head 34 shown in FIG. The comparative example shown in FIG. 8 differs from the configuration shown in FIG. 7 in that the first filter 339 is disposed below the central position in the vertical direction in the first air circulation chamber 332b. Yes.

  Specifically, the first filter 339 is disposed at a distance H1a from the upper surface of the first air circulation chamber 331b (the bottom surface of the guide member 332) and a distance H2a from the bottom surface of the first air circulation chamber 331b. However, the distance H2a is shorter than the distance H1a. In other words, the first filter 339 is disposed below the central position in the vertical direction in the first air circulation chamber 331b.

  Air flows along arrows FC1a and FC2a shown in FIG. The wind indicated by the arrow FC2a blows from the first filter 339 toward the first negative pressure generator 336b. As shown in FIG. 8, since the first filter 339 is disposed below the center position in the vertical direction in the first air circulation chamber 331b, the first filter 339 is connected to the first negative pressure generator 336b. Pressure loss due to air flow increases. Therefore, in the first air circulation chamber 331b, the negative pressure in the space above the first filter 339 decreases, so the ability to remove mist staying in the vicinity of the recording head 34 decreases.

  Next, a case where the suction fan of the second negative pressure generating unit 336a is reversed will be described with reference to FIG. FIG. 9 is a diagram showing the air flow when the suction fan of the second negative pressure generating unit 336a shown in FIG. 2 is reversed.

  When the suction fan of the second negative pressure generating part 336a is reversed, air is sucked from the second exhaust port 337a, and the atmospheric pressure in the second air circulation chamber 331a becomes larger than the atmospheric pressure. Therefore, the air in the second air circulation chamber 331a is discharged into the narrow space 35a through the through hole 335 in the direction indicated by the arrow FD3. By this air flow, the paper dust collected on the upper surface of the second filter 338 is discharged into the narrow space 35a through the through hole 335.

  On the other hand, since the suction fan of the first negative pressure generator 336b is rotating forward, a negative pressure is generated in the first air circulation chamber 331b. Therefore, the air in the vicinity of the recording head 34 is sucked into the first air circulation chamber 331b through the through hole 335 in the direction indicated by the arrow FD5. With this air flow, the air in the vicinity of the narrow space 35a flows in the direction indicated by the arrow FD4 (leftward in FIG. 9).

  As described above, since air flows along the arrows FD3, FD4, and FD5, the paper dust collected on the upper surface of the second filter 338 is discharged to the narrow space 35a, and then the first filter. 339 is collected on the upper surface of 339. Therefore, since the paper dust on the upper surface of the second filter 338 can be moved to the upper surface of the first filter 339, the replacement frequency of the second filter 338 can be reduced.

  Next, a comparative example of the filter 338 and the filter 339 shown in FIG. 2 will be described with reference to FIG. FIG. 10 is a side cross-sectional view illustrating a configuration of a comparative example of the filter 338 and the filter 339 illustrated in FIG. As shown in FIG. 10, the filter 338 (339) is disposed on the upper surface of the guide member 332.

  Since the filter 338 (339) is disposed on the upper surface of the groove 334 formed in the guide member 332, the sliding resistance with the transport belt 32 (see FIG. 3) increases. Further, since the conveyor belt 32 (see FIG. 3) slides on the upper surface of the filter 338 (339), the filter 338 (339) may be worn or damaged such as fuzzing.

  The embodiments of the present invention have been described above with reference to the drawings. However, the present invention is not limited to the above-described embodiment, and can be implemented in various modes without departing from the gist thereof (for example, (1) to (4) shown below). For ease of understanding, the drawings schematically show each component as a main component, and the thickness, length, number, etc. of each component shown in the drawings are different from the actual for convenience of drawing. There is a case. Moreover, the shape, dimension, etc. of each component shown by said embodiment are an example, Comprising: It does not specifically limit, A various change is possible in the range which does not deviate substantially from the structure of this invention.

  (1) In this embodiment, the case where the conveyance belt 32 conveys the paper P in the image forming unit 3 has been described. However, the image forming unit 3 may convey the paper P by other methods. For example, the paper P may be transported by a plurality of transport rollers. In this case, it is preferable to apply a negative pressure from between adjacent conveyance rollers.

  (2) In the present embodiment, the case where the narrow space 35a is formed by the plate-like member 35 has been described. However, the narrow space 35a may be formed by other methods. For example, the head base that supports the recording head 34 may be formed so as to protrude toward the conveyance belt 32 on the upstream side in the conveyance direction D1 of the paper P with respect to the recording head 34 to form the narrow space 35a. In this case, the structure can be simplified.

  Further, instead of the plate-like member 35, the narrow space 35a may be formed by a belt stretched around two rollers. Specifically, a driving roller and a driven roller disposed at a position substantially parallel to the upper surface of the conveyance belt 32, and an endless belt stretched around the driving roller and the driven roller, A narrow space 35 a is formed between the lower surface and the upper surface of the conveyor belt 32. In this case, when the paper dust adheres to the lower surface of the endless belt, the endless belt can be driven to rotate so that the surface to which the paper dust does not adhere is located on the lower side. The frequency with which the man removes the paper dust adhering to the endless belt can be reduced.

  (3) In this embodiment, although the case where the 2nd filter 338 was comprised from a nonwoven fabric was demonstrated, the form comprised from another material may be sufficient. For example, the second filter 338 may be a mesh filter. In this case, the pressure loss due to the second filter 338 can be reduced.

  (4) In the present embodiment, as illustrated in FIGS. 6 and 7, the case where the guide grooves 331 d to 331 g are provided has been described, but other forms may be used. For example, a form in which support members for supporting the frame bodies 338 b and 339 b of the filters 338 and 339 are arranged on the side wall of the air circulation chamber 331 may be employed. In this case, the configuration of the air circulation chamber 331 is simplified.

  The present invention is applicable to an ink jet recording apparatus.

DESCRIPTION OF SYMBOLS 1 Inkjet recording device 2 Paper feed part 3 Image formation part 31 Conveyance part 312 Adsorption roller 32 Conveyor belt 321 Suction hole 33 Negative pressure application part 33a Second negative pressure application part 33b First negative pressure application part 331 Air circulation chamber 331a Second Air circulation chamber 331b First air circulation chamber 331d to 331g Guide groove 332 Guide member 334 Groove 335 (335a, 335b) Through hole 336 Negative pressure generating portion 336a Second negative pressure generating portion 336b First negative pressure generating portion 338 Second filter 339 First filter 338a, 339a Filter body 338b, 339b Frame 34 (34a, 34b, 34c, 34d) Recording head 35 Plate member (space forming portion)
35a Narrow space 36 Transport guide 4 Paper transport section 5 Paper discharge section

Claims (8)

A recording head for discharging ink onto the recording medium;
A transport unit for transporting the recording medium to an image forming position by the recording head;
A first negative pressure application unit that applies a negative pressure to the recording medium at the image forming position,
The first negative pressure applying unit includes a first negative pressure generating unit that generates a negative pressure, a first negative pressure chamber that stores negative pressure air generated by the first negative pressure generating unit,
A space forming portion that forms a narrow space between the recording head and the recording medium on the upstream side in the conveyance direction of the recording medium with the recording medium placement surface in the conveyance unit;
In the first negative pressure chamber, a first filter is disposed substantially parallel to a plane perpendicular to the thickness direction of the recording medium conveyed to the image forming position,
The first filter blocks the ink and allows air to pass through,
The space forming unit includes a plate-like member having a flat surface facing the mounting surface of the recording medium in the transport unit and substantially parallel to the mounting surface of the recording medium,
The transport unit is
A transport belt for transporting the recording medium;
A guide member that supports the recording medium via the conveyor belt;
The guide member has a plurality of grooves and a plurality of through holes,
Each of the plurality of grooves is formed on the surface of the guide member on the conveying belt side, and extends in the conveying direction of the recording medium.
Each of the plurality of through holes penetrates the guide member in the thickness direction, and communicates each of the plurality of grooves with the first negative pressure chamber,
With respect to the projection image of the plate-like member onto the guide member, the through holes are formed in a row on each of the upstream side in the transport direction of the recording medium and the downstream side in the transport direction of the recording medium,
Of the plurality of grooves, a groove communicating with the through-hole formed on the upstream side conveys the recording medium further than the position of the upstream end in the conveyance direction of the recording medium in the projection image of the plate-like member. Extending upstream in the direction,
Of the plurality of grooves, the groove communicating with the through hole formed on the downstream side further conveys the recording medium than the position of the downstream end in the conveyance direction of the recording medium in the projection image of the plate-like member. An ink jet recording apparatus extending downstream in the direction.   2. The ink jet recording apparatus according to claim 1, wherein the first filter is disposed above a center position in a thickness direction of the first filter in the first negative pressure chamber. A second negative pressure application unit that applies a negative pressure to the recording medium conveyed below the narrow space;
The second negative pressure application unit includes a second negative pressure generation unit that generates a negative pressure, and a second negative pressure chamber that stores the negative pressure air generated by the second negative pressure generation unit,
In the second negative pressure chamber, a second filter is disposed substantially parallel to a plane perpendicular to the thickness direction of the recording medium conveyed below the narrow space,
The inkjet recording apparatus according to claim 1, wherein the second filter blocks paper dust and allows air to pass therethrough.   The inkjet recording apparatus according to claim 3, wherein the first filter and the second filter are detachably disposed from the first negative pressure chamber and the second negative pressure chamber, respectively. Guide grooves are respectively formed on the side walls of the first negative pressure chamber and the second negative pressure chamber,
The guide groove is formed substantially parallel to a plane perpendicular to the thickness direction of the recording medium being conveyed by the conveyance unit, and the first filter and the second filter are attached and detached when the first filter and the second filter are attached and detached. The inkjet recording apparatus according to claim 4, wherein both ends of the filter and the second filter are guided. The said 1st filter and the said 2nd filter are arrange | positioned separately from the said 1st negative pressure chamber and the said 2nd negative pressure chamber so that removal is possible, The any one of Claims 3-5. Inkjet recording apparatus. The first negative pressure generation unit and the second negative pressure generation unit respectively include a first suction fan and a second suction fan that are different from each other,
The second suction fan is configured to be reversible,
When the second suction fan reverses, air is sent from the outside into the second negative pressure chamber by the second suction fan,
The inkjet recording apparatus according to claim 3, wherein the first suction fan generates a negative pressure in the first negative pressure chamber.   The inkjet recording apparatus according to any one of claims 1 to 7, wherein the plate-like member is a conductor having at least a lower surface thereof grounded.

Images